Optical systems transmit light through various media, such as air or light transmissive materials. Such optical systems employ one or more lenses to focus and condition the transmitted light. One exemplary lens is a ball lens, also known as a Luneberg lens. Some optical systems are relatively small. Ball lenses may be used in various Micro-Electro-Mechanical Systems (MEMS) optical technologies. FIG. 1 is a simplified block diagram of a light source 102 and a ball lens 104 deployed in a prior art MEMS optical system 106. Emitted light 108 enters the ball lens 104. The light is then focused by the ball lens 104, and exits as focused light 110.
Typically, ball lens is separately formed from the MEMS optical system, and then picked and placed into position using a manual or automated technique. The location of the ball lens in the MEMS optical system may be controlled by etching or machining a suitable ball lens receptacle, such as depression or the like, into a supporting substrate. Thus, the ball lens is placed in a desired location when the ball lens is placed into its receptacle.
In some applications, gravity may aid in the placement of the ball lens into its respective receptacle. That is, gravity helps position the ball lens so that it lies at the lowest contact points of its receptacle, such as the four side walls of an inverted pyramid receptacle. In other systems, a force may be applied to the ball lens to place it into its intended position in the substrate. If desirable, the positioned ball lens may be attached to the substrate with an adhesive or by use of another suitable fastening means.
Precise control of the placement of a relatively small ball lens may be difficult. And, in some situations, the ball lens may inadvertently move out of its intended location on the substrate. Further, as MEMS optical systems become increasingly smaller, it may be desirable to use light focusing lenses that are smaller than a conventional ball lens.